When nickel is added in ASME SA 572 Gr. 50 Carbon Steel Perforated Coils, for instance, the austenite structure of iron is stabilized. ASTM A572 Gr. 42 CS Plates have a mixed microstructure of austenite and ferrite, the aim usually being to produce a 50 / 50 mixes, although in commercial alloys the ratio may be 40 / 60. ... ASTM A572 Grade 42 ...